COLBY - A new Marathon County complaint against a former Abbotsford High School math teacher alleges that his sexual assaults of one student lasted into the beginning of this year, longer than alleged in a previous complaint.

The student is one of two listed in a Clark County complaint against Andy Follen, 26, of Spencer, who is accused of having sexual contact with two female students. The sexual assault of one girl happened in December 2013 while sexual assaults of the other girl happened between October and December 2013, according to that complaint.

Two additional charges of sexual assault of a student were filed against him in Marathon County Circuit Court on Tuesday, according to court records.

The new complaint alleges that additional sexual contacts between Follen and the student, who was 17 years old at the time, happened between Jan. 1 and Jan 31 of this year in the city of Colby.

He faces a maximum of 42 years in prison if convicted on all charges in both counties.

An investigation began in January 2014 after the school reported to police that it was looking into allegations that Follen might have had "inappropriate relationships" with some of his students, according to the Clark County complaint. He submitted a letter of resignation the same day, according to the complaint.

His first court appearance on new charges in Marathon County Circuit Court is scheduled for Oct. 16. His next court date in Clark County is scheduled for Dec. 1 and a jury trial in the case is scheduled to begin Feb. 9, 2015, according to court records.